Tbilisi, Georgia ? Georgia’s parliamentary speaker cut short a foreign trip after the death of Prime Minister Zurab Zhvania and returned to the stunned republic Friday, urging the government to retain its momentum in reinvigorating the country.

Parliament speaker Nino Burdzhanadze, an ally of Zhvania and President Mikhail Saakashvili, returned from a private visit to Italy and called on the government to continue working as usual despite “a big loss for Georgian politics and the Georgian state.”

Zhvania, 41, was found dead early Thursday at a friend’s home, apparently poisoned by carbon monoxide from a gas-fired heating stove. Initial tests showed Zhvania’s blood had nearly double the fatal level of carbon monoxide, a forensics service spokeswoman said. His host also died.

Authorities called Zhvania’s death an accident, but many people in Georgia — plagued by a history of political intrigue, conflicts with breakaway regions and tense relations with Russia — were skeptical. One lawmaker linked Zhvania’s death and a car bombing Tuesday near separatist South Ossetia, and hinted at Russian involvement.

A small knot of mourners gathered for a second day Friday outside the home of Zhvania’s mother in central Tbilisi. Rudimentary repairs were swiftly made to the old brick building’s dilapidated facade, and flowers were laid on a windowsill outside Rimma Zhvania’s first-floor apartment.

A wooden coffin was delivered to her home Thursday. Zhvania’s body will be moved to the capital’s Holy Trinity Cathedral for public viewing today before Sunday’s funeral.

On Thursday, a visibly shaken Saakashvili lit candles in Zhvania’s honor at the cathedral and urged Georgians to remain calm.

“I assume control over the executive branch and I call on members of the Cabinet to return to work and to continue their work as normal,” said Saakashvili, who appointed Zhvania after his election in January 2004 — rewarding a key ally in the November 2003 protests against election fraud that became known as the “Rose Revolution.”

Zhvania was considered a moderate in the government of the fiery Saakashvili, and worked to overcome endemic corruption that had enriched some officials during the era of ex-president Eduard Shevardnadze while the economy deteriorated.